2005 Mitsubishi Lancer Intermittent engine failure

Engine Mechanical problem
2005 Mitsubishi Lancer 4 cyl Front Wheel Drive Automatic

My father has a 2005 Lancer ES auto that periodically loses all power, goes into limp mode and the check engine warning lamp comes on. Usually switching the engine off / on sets it right again.

The last time it went to the dealers for a service, the mechanics "couldn't find anything wrong". I am taking it in for its next service and I'd like some ideas as to what could cause the engine to almost completely quit.

It doesn't happen often, but it has been happening since it was new.

Any ideas to help me point out areas for the mechanics to look at?

Thanks.